Air-superheater for steam-boiler furnaces.



Patented May 26, 1914- 5&

R. WEAVER.

AIR SrUPERHEATER FOR. STEAM BOILER FURNACES.

APPLICATION FILED JUNE 5, i911.

bil INVENTOR WITNESSES BY g PLANOOIAI'H (10.. wAsnmo ATTO R N EY Tom-wt.

COLUMBIA R WEAVER AIR SUPERHEATEB. FOR. STEAM BOILER FURNACES.

v APPLICATION FILED JUNE 5, 1911. 1,097,

Patented May 26, 1914.

2 SHEETS-SHEET 2.

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WITNESSES INVENTOR ATTO RN EY TTNTTE RALPH WEAVER, 0F ATLANTA, GEORGIA.

AfltfiUPERHEATER FOB. STEAM-BOILER FURNACES.

Application filed June 5, 1911.

specification of Letters Patent.

Patented May 26, 1914.

Serial No. 631,375.

To aZZ whom it may concern Be it known that l, RALPH VVnavnn, a citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented a new and useful Air-Superheater for SteanrBoiler Furnaces, of which the following is a specification.

The invention relates to improvements in air superheaters for steam boiler furnaces.

The object of the present invention is to improve the construction of air superheaters for steam boiler furnaces, and to provide a simple, inexpensive and efficient air superheater, designed for use in connection with various types of steam boiler furnaces, more particularly return tubular boilers, and having a maximum amount of heating surface, arranged exterior-1y of the bridge and baffle walls and exposed to the direct action of the heat and flames of a furnace, whereby the air passing through the superheater is raised to a sufficiently high temperature to produce a most perfect degree of combustion and consume the smoke and the gases, which usually pass off with the same to the stack,

thereby increasing the generation of the steam and reducing the cost of operating such furnaces.

With these and other objects in View, the invention consists in the construction and novel combination of parts hereinafter fully described, illustrated in the accompanying drawings, and pointed out in the claims hereto appended; it being understood that various changes in the form, proportion, size and minor details of construction, within the scope of the claims, may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawingss-Figure 1 is a perspectiveview of an air superheater, constructed in accordance with this invention, and shown applied to a furnace, the latter being in section. Fig. 2 is a longitudinal sectional view of the same, the boiler being shown in elevation. Fig. 3 is a transverse sectional view on the line 3-3 of Fig. 2. Fig. 4 is a transverse sectional view on the line 4ll of Fig. 2. Fig. 5 is a horizontal sectional view on the line 55 of Fig. 2. Fig. 6 is a similar view on the line 6() of Fig. 2. Fig. 7 is a vertical sectional View on the line 77 of Fig. 2. Fig. 8 is a similar view on the line 88 of Fig. 2.

Like numerals of reference designate cor responding parts in all the figures of the drawings.

In the embodiment of the invention illustrated in the accompanying drawings, the superheater is applied to a furnace of a return tubular boiler type, having a bridge wall 1, extending across the furnace and supporting the rear or inner ends of the grate bars 2, and constructed in the usual manner of masonry, brickwork, or other suitable material. The bridge wall, which extends entirely across the furnace, is spaced from the boiler 3 to provide the usual smokeway or passage for the products of combustion, and it is provided at an intermediate point between its top and bottom with spaced air passages or flues l, preferably metal lined extending longitudinally of the furnace and communicating at the front ends with the ash pit opposite the doors thereof, and equipped with slidable dampers 5, mounted in suitable horizontal guides 6 and adapted to control the passage of air through the fines or ducts and enabling a proper amount of air to be supplied to the furnace. The air passages or ducts d, which taper forwardly, as clearly illustrated in Fig. (3 of the drawings, are preferably formed by iron fines or tubes, mounted in the masonry of the bridge wall, but they may be constructed in any other preferred manner and of any suitable material. The mouths or inlets of the air passages or lines t are located at the front face of the bridge wall directly under the grate bars, and they are thereby enabled to take heated air from the ash pit at a sufficient distance from the bottom thereof to prevent them from becoming clogged with ashes.

The rear ends of the passages or fines 4L communicate with horizontal rearwardly extending base air Hues or tubes 7 of substantially oblong shape and rectangular in cross section, and constructed of noncombustible clay, or any other non-combustible material. The horizontal tubes or flues 7, which also extend longitudinally of the furnace, form continuations of the passages or flues t and are supported upon a horizontal extension 8 of the bridge wall, and are provided with rear end walls 9 closing the rear ends of the base tubes or flues 7, as clearly illustrated in Fig. 2 of the drawings. The extension 8 is of a width less than the spaces between the side walls of the furnace, and it is of a length to correspond with the length of the bottom flues 7, and it has its upper face arranged in substantially flush relation with the bottoms of the air flues or passages 4 of the bridge wall. The base flues or tubes 9 are provided in their upper walls with openings, and they communicate with and support upright tubes or flues 10, mounted upon the base tubes or flues 9 and having lower reduced ends 11, which fit in the openings of the tubes or flues 9, but any other form of joint may be employed, as will be readily understood. The upper ends 12 of the vertical tubes or flues are also exteriorly recessed or reduced to fit in bottom openings of horizontal top tubes or flues 13, and they are spaced from each other and also from the rear face of the bridge wall to permit the heat to pass around the upright tubes or flues 10, and cause the flames to wrap around the same to produce a large amount of superheat. The upright tubes or flues 10 and the top horizontal tube or flue are constructed of non-combustible clay, or other non-combustible material similar to the base tubes or flues, and the front ends of the top tubes or flues extend to the bridge wall and are supported upon the same at the rear face thereof. The supported front terminals of the top tubes or flues 13 fit within openings 1% in rear walls 15 of superheated caps 16, arranged upon the bridge wall and extending from the front face thereof to the rear face of the same and entirely across the furnace between the side walls thereof to form a superheater of the entire top of the bridge wall and composed of a top wall, side walls and a rear end wall, the

superheater caps being open at the bottom,

and the upper face of the top of the bridge wall constituting the bottom of the passages within the caps. The caps 16 are preferably made in two sections, the top wall being divided, as shown, and connected by a tongue and groove joint 17, or other suitable form of joint. Each of the superheater caps is provided with spaced integral division walls or partitions 18, tapered rearwardly and extending longitudinally of the furnace and from the front of the cap to within a short distance of and spaced from the opening of the rear wall, and having their points or apexes located opposite the front end of the tube 13 in position for dividing the current of air passing through the same. The passages formed by the division walls or partitions 18 are disposed longitudinally of the furnace and have their discharge outlets located at the front face of the bridge wall at the top thereof opposite the stoking doors of the furnace. By arranging the upper and lower passages of the air superheater longitudinally of the furnace and by locating the front ends of the upper passages at the front of the bridge wall opposite the stoking doors, and the front ends of the lower passages or flues 4: at the front of the bridge wall opposite the doors of the ash pit, ready access is afforded to the flues or passages from the front of the furnace, and the said flues or passages may be readily cleaned, as hereinafter fully explained. The superheater cap is also provided with spaced longitudinal flanges 19, located in the spaces or passages formed by the longitudinal division walls or partitions 1S and depending from the top wall of the cap and terminating short of the top of the bridge wall, the lower edges of the longitudinal flanges 19 being located above the plane of the lower edges of the walls and the partitions 18, which extend from the top of the cap to the plane "of the lower edges of the rear end and side walls, and rest upon the bridge wall and constitute supports for the cap. The cap is thereby adapted to be divided longitudinally into separate sections without impairing its strength.

The superheater caps are of greater cross sectional area than the top tubes or flues 13 to permit the air to expand within the su perheater caps and the longitudinal flanges 19, which finely divide the separate currents of air, present highly heated surfaces to the same and they terminate short of the front ends or outlets of the passages, formed by the division walls or partitions 1S and also short of the rear ends of the latter, as clearly illustrated in Fig. 5 of the drawings. By terminating the longitudinal flanges short of the bottom of the passages of the superheater caps, cleaning spaces are provided at the bottoms of the passages to permit the superheater caps to be readily cleaned. The bottom cleaning spaces are of a width equal to the width of the passages of the superheater caps and extend the entire length of the same. The cleaning may be done by first breaking off the honey comb, which accumulates at the discharge outlets of the superheater caps, and a scraper or a steam jet may then be used for cleaning the passages of the superheater caps and the con necting flues. When a scraper is used the soot or other accumulation may be pushed rearwardly through the superheater cap and the top flues 13 and caused to fall down the upright flues 10, and such accumulation may be removed from the lower ends of the latter liberated gases, which usually pass off with the smoke, and it commingles with the same and is of sufficiently high temperature, 0W- ing to the exterior arrangement of the superheaters to produce a most perfect degree of combustion, which results in consuming the smoke and gases and in the production of a higher degree of heat.

The furnace is equipped with a battle wall 20 spaced from the bridge wall and supporting the boiler 3 and having an opening 21 for the passage of the smoke and other prod nets of combustion. Within the opening 21 at opposite sides thereof are arranged vertical superheater tubes or lines 22, preferably built into the baffle wall at the opening 21 and arranged exterior-1y of the brick-work or masonry of the same so as to be completely subjected to the heat of the furnace for raising the superheated air to a sufficient temperature to produce combustion for consuming any of the carbonaceous products unconsumed at the bridge wall. Each of the upright superheater tubes or lines 22, which are constructed of non-combustible material, is provided at its front wall, or the wall constituting the side wall of the opening 21 with a vertical series of discharge apertures 23, gradually increasing in size from the bottom to the top of the series and arranged to discharge superheated air at the constricted passage, formed by the opening of the baffle wall, whereby a 1naximum effect of the superheated air in its action on the unconsmned carbon is obtained. The furnace is also provided at the baffle wall with eXteriorly arranged upright tubes or lines 24 fitted against the upright tubes or flues 22 and arranged in rear thereof and adapted to supplement the action of the same. The rear upright tubes or flues 24 are constructed of non-combustible clay, or any other non-combustible material similar to the upright tubes or fines 22, and by being arranged exteriorly of the baffle wall they are thoroughly subjected. to the action of the heat.

The tubes or flues 24- are provided in their front walls with a vertical series of discharge apertures 25, gradually increasing in size from the bottom to the top of the series, similar to the outlets 23, as clearly illustrated in Fig. 2 of the drawings. The upright tubes or flues 22 and 24 are connected at their lower ends with rearwardly extending horizontal conduits 26, constructed of sections of non-combustible clay, or any other suitable non-combustible material and opening through the rear walls of the furnace and equipped at their outer ends with slidable dampers 27. The sections are provided at their terminals with interfitting male and female ends, which form connecting joints 26, but oints of any other desired construction may of course be employed. The horizontal rearwardly extending conduits are divided longitudinally by horizontail partitions 28 into upper and lower passages 29 and 30, communicating, respectively, with the upright tubes or flues 2t and 22. The longitudinal partition 28 terminates short of the inner or front end of the horizontal conduit and is extended at its front end 31 to the top wall of the conduit to close the upper passage 29 at the front end, as clearly illustrated in Fig. 2 of the drawings. The lower passage 30 extends forward in advance of the upper passage and thereby communicates with the lower end of the upright tube or flue 22. The flues 22 and 24 are provided at their lower ends in their outer side walls with openings and 33, which eomnuinicate with the longitudinal passages 29 and 30 of the horizontal conduit 2G, and the latter is located to one side of the longitudinal plane of the upright superheater tubes or fines 22 and 21-. The longitudinal conduit may, however, be connected with the upright superheatcr tubes or lines 22 and 2a in any other preferred manner. The slidable damper 27 is mounted in suitable guides 34:, and is adapted to be adjusted to vary the size of the inlet of the longitudinal conduit. The draft from the stack is sufficient to draw the air through the passages of the superheater to their full capacity, and the amount of air delivered to the furnace may be controlled to suit the character of the fuel used and the other furnace conditions.

No claim is made in the present application to the construction of the batlle and the super-heater thereof,

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A furnace including a boiler, grate bars, a bridge wall, a superheater cap arranged exteriorly of the bridge wall and mounted upon the top thereof between the same and the boiler and provided with a passage located above the bridge wall and extending longitudinally of the furnace and having an outlet located. at the front end of the super-heater cap and at the front face of the bridge wall, said superheater cap being also provided with longitudinal flanges arranged within the said passage and subdividing the same and presenting heating surfaces against which the air impinges, said flanges depending from the top of the superheater cap and tern'linating short of the bottom of said passage so as to leave an open cleaning space at the bottom, and an air passage communicating with the passage of the superheater cap.

2. A furnace including a boiler, grate bars, a bridge wall, a superheater cap separate from the bridge wall and mounted upon the same exteriorly thereof and provided with a passage extending longitudinally of the furnace and having an. outlet at the front located at the front face of the bridge wall opposite the stoking doors of the furnace, said superheater cap being also provided with longitudinal flanges arranged within the said passage and subdividing the same and presenting heating surfaces against which the air impinges, said flanges depending from the top of the superheater cap and terminating short of the bottom of said passage so as to leave an open cleaning space at the bottom, and an air passage communieating with the passage of the superheater cap.

3. A furnace including a boiler, grate bars, a bridge wall, a superheater cap mounted upon the top of the bridge wall and provided at the back with an opening and having a longitudinal partition located opposite the rear opening and arranged to split the current of air and dividing the cap into passages, which extend longitudinally of the furnace, said superheater cap being also provided with longitudinal flanges arranged within the said passages and sub-dividing the same and providing heating surfaces against which the air impinges and terminating short of the bottom of the passages to leave open cleaning spaces thereat, and an air passage communicating with the rear opening of the superheater cap.

i. A furnace including a boiler, grate bars, a bridge wall, a superheater cap mounted upon the top of the bridge wall and provided at the back with an opening and having a longitudinal partition located opposite the rear opening and arranged to split the air and dividing the cap into air passages, which extend longitudinally of the furnace, said superheater cap being also provided with longitudinal flanges arranged within the said passages and sub-dividing the same and presenting heat-ing surfaces against which the air impinges, said flanges depending from the top of the superheater cap and terminating short of the bottom of said passage so as to leave open cleaning spaces at the bottom, and an air passage communicating with the opening of the superheater cap.

A furnace including a boiler, grate bars, a bridge wall, a super-heater cap mounted upon the bridge wall and composed of a top, side walls and a rear wall having an opening, longitudinal partitions located opposite the rear opening of the cap and dividing the latter into a plurality of separate passages, which extend longitudinally of the furnace, said partitions being tapered rearwardly to split the current of air and the said superheater cap being provided in the said passages with longitudinal flanges depending from the top wall of the cap and terminating short of the bottoms of the passages so as to leave open cleaning spaces thereat and presenting a plurality of heating surfaces to the air, and an air passage communicating with the rear opening of the superheater cap.

6. A furnace including a boiler, grate bars, a bridge wall, a superheater cap mount-- ed upon the bridge wall and composed of a top, side walls and a rear wall having an opening, longitudinal partitions located opposite the rear opening of the cap and dividing the latter into a plurality of separate passages, which extend longitudinally of the furnace, said partitions being tapered rearwardly to split the current of air, and flanges arranged in parallelism and extending longitudinally of the passages and depending from the top wall of the cap and terminating short of the upper face of the bridge wall and the front ends of the said passages, and an air passage connected with the rear opening of the superheater cap.

7. A furnace including a boiler, grate bars, a bridge wall, superheater caps mount ed upon the top of the bridge wall and comprising top walls and side walls, the top of the bridge wall constituting the bottom of the superheater caps, the latter being pro vided with partitions extending longitudinally of the furnace and terminating short of the rear ends of the superheater caps and forming separate longitudinal passages, and projecting portions depending from the top wall of the superheater caps into the path of the air and terminating short of the bottom of the passages so as to leave lower cleaning spaces, and an air passage communicating with the superheater caps.

In testimony, that I claim the foregoing as my own, I have hereto aiiiXed my signature in the presence of two witnesses.

RALPH WEAVER.

ll itnesses Enrznsr HOWARD,

C. S. Davis.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Fatents, Washington, I). 0. 

